[Droid Eris Q&A, Help & Troubleshooting] bftb0:
Executive summary: just get the engineering bootloader (1.49.2000 S-OFF) installed on your phone, and flash radios using fastboot (being very very careful to verify MD5 signatures). If you are going to be flashing stuff to your phone frequently, you really want the S-OFF bootloader on your phone for disaster recovery reasons anyway.

OK, I ran a fairly long experiment on your behalf, and it went like this:

- flash 2.42.02.10.29.zip from Amon_RA (succeeded; bootloader was 1.49.2000 S-OFF)

- flashed older radio (2.42.00.04.12) image file back into place using fastboot (not Amon_RA)

- Downgraded my bootloader to 1.49.000 S-ON using fastboot

- flash 2.42.02.10.29.zip from Amon_RA (failed; bootloader was 1.49.0000 S-ON)

- Upgraded my bootloader using "erisengspl.zip" + Amon_RA **** back to 1.49.2000 S-OFF

- flash 2.42.02.10.29.zip from Amon_RA (failed; bootloader was 1.49.2000 S-OFF)

- rebooted once (into OS) and then booted into recovery

- flash 2.42.02.10.29.zip from Amon_RA (succeeded; bootloader was 1.49.2000 S-OFF)

So, I was expecting to see that your trouble had something to do with your bootloader version - especially after seeing the first failure that I observed ... but then I was able to get it to both succeed and fail using the same S-OFF (1.49.2000) bootloader - and the only thing which changed was that I rebooted once between the trial that succeeded, and the trial which failed.

At that point, I did not go back and re-run any trials with the 1.49.0000 S-ON bootloader to see if I could get it to suceed - because it was evident that something else was going on.

Some of this is not entirely unexpected. When you flash either of the firmware images (either the radio or the bootloader image files), it is actually the bootloader that does the flashing, not the recovery boot: that's why the recovery tells you to "reboot .... to complete the installation". What the recovery does is to "stage" the image file (in /cache, I suspect), and then write some instructions into the "misc" partition that tell the bootloader what to do the next time the phone resets.

That's why - when things work correctly - the phone momentarily goes dark, you see a graphic image on the screen (that suggests that flashing is taking place), and then the phone reboots again ... and ends up back in the recovery boot !! (You will have to take my word for it, if you don't remember what it looks like). That "flashing" graphic image is put up on the screen by the bootloader; when it finishes up, it chains back to the recovery boot ... and communicates to the recovery (via the either the misc partition or the cache partition), "hey, wipe the /cache partition as soon as you start up". (Note the implications - the next OS reboot will need to rebuild the dalvik-cache(s))

The thing is, "misc" gets written to every time the phone shuts down or boots up - whether we are talking about starting from the OS, from the recovery boot, from fastboot mode, or from RUU mode - and how many different ways are there to reboot?

- battery pull

- fastboot reboot-recovery

- fastboot reboot

- adb shell reboot bootloader

- adb shell reboot recovery

- reboot Amon_RA from menu

- (cold start) -> fastboot mode -> hboot mode -> recovery

- (cold start) -> hboot mode -> recovery

- (cold start) -> recovery

In any event, if you want to tease this all out, with some experimenting around with the way that you get into the recovery boot, you can probably get the flashing method to work. ( For instance, you could probably use an adb shell session with Amon_RA running to "flash_image misc misc.img", where "misc.img" is the image file from jcase's "Flash Any RUU post" - and then use the flashable radio .zip file from within Amon_RA. )

But, as I mentioned above, it is a lot easier to just punt and install radios using fastboot and the S-OFF bootloader. Just be sure you have triple-checked everything before you hit the Enter key.

bftb0

**** EXTREMELY DANGEROUS UNLESS THE EXISTING BOOTLOADER IS 1.49.0000 - "erisengspl.zip" has hard-bricked phones that had 1.46.0000 bootloaders!